Custom Add-in Development
Modernize your email experience. From Outlook web add-in development to Gmail add-ons, our expert engineering team builds seamless inbox integrations.
The Legacy Add-in Bottleneck
Legacy COM/VSTO add-ins are fundamentally broken in the modern cloud era. They crash Outlook, are impossible to deploy on Macs or mobile devices, and block enterprises from migrating fully to Microsoft 365.
VSTO Deprecation
Migrate your VSTO COM add-in to Office.js. Microsoft is heavily pushing the web-based add-in model, leaving COM/VSTO add-ins behind in terms of support and cross-platform functionality.
Cross-Platform Needs
Your team needs add-ins that work on Windows, Mac, iOS, Android, and the browser. Only modern Outlook Web Add-ins and Gmail Add-ons can deliver this.
Niche Expertise
Building for the inbox is notoriously difficult. Quirks in the Office.js API and Gmail's Card Service require highly specialized engineering knowledge.
Hire Office.js & Gmail Add-in Developers
MailGovern's engineering team has spent years mastering the complexities of inbox integrations. We offer end-to-end development services for custom add-ins.
- Full-cycle Outlook web add-in development (Office.js).
- Seamless Gmail add-on development via Google Workspace.
- Complex legacy VSTO COM to Office.js migrations.
- UI/UX designed specifically for the narrow inbox taskpane.
Ready to build your add-in?
Let's discuss your Outlook or Gmail integration requirements.
Book a Consultation